The present invention relates to an improvement of a filter device attached to a fuel intake port in a fuel tank for preventing water or foreign matters from entering fuel to be transferred to an internal combustion engine through the fuel intake port.
Patent References No. 1 to No. 3 have disclosed filter devices to be attached to a fuel intake port in a fuel tank of an automobile, motorcycle or the like for preventing water or foreign matters from entering fuel to be transferred to an internal combustion engine through the fuel intake port.
Those filter devices include a filter member formed in a bag shape; a space forming member for retaining the filter member in an expanded bag shape; and a connecting portion formed in a cylindrical shape communicating with an interior space of the filter member and having a cylindrical upper end attached to the fuel intake port.
However, in these filter devices, in view of the structure, the following steps are required for production.
(1) A step of cutting a filtering material constituting a filter member;
(2) A step of integrally attaching the connecting portion to the filtering material by injection molding of a plastic with the filtering material as an insert;
(3) A step of applying heat seal to the filtering material and forming the filtering material into a filter member with a bag shape after wrapping a space forming member with the filtering material; and
(4) A step of cutting an unused portion of the filter member outside the thermal seal.
Also, in these filter devices, the connecting portion is attached to the filtering material by an insertion molding. Accordingly, it is necessary to form the filter member with a synthetic resin material having good compatibility with a synthetic resin material constituting the connecting portion.
Patent Reference No. 1
Japanese Patent Publication (Kokai) No. 2003-28019
Patent Reference No. 3
Japanese Patent Publication (Kokai) No. 2003-42033
Patent Reference No. 3
Japanese Patent (Kokai) No. 3353986
In view of the problems described above, an object of the invention is to provide a fuel filter device which can be easily and appropriately produced.
Further objects and advantages of the invention will be apparent from the following description of the invention.